U.S. patent application number 13/635248 was filed with the patent office on 2013-01-10 for method for determining the activity of the parasympathetic nervous system and/or the sympathetic nervous system of the autonomic nervous system of a living being.
Invention is credited to Ralf Arne Wittling, Werner Wittling.
Application Number | 20130009779 13/635248 |
Document ID | / |
Family ID | 44585471 |
Filed Date | 2013-01-10 |
United States Patent
Application |
20130009779 |
Kind Code |
A1 |
Wittling; Werner ; et
al. |
January 10, 2013 |
METHOD FOR DETERMINING THE ACTIVITY OF THE PARASYMPATHETIC NERVOUS
SYSTEM AND/OR THE SYMPATHETIC NERVOUS SYSTEM OF THE AUTONOMIC
NERVOUS SYSTEM OF A LIVING BEING
Abstract
The invention relates to a method for determining the activity
of the parasympathetic nervous system or of the sympathetic nervous
system of the autonomic nervous system of a living being, in
particular a human being, wherein a feature of the condition of the
living being is determined, and the activity is determined from the
feature of the condition. According to the invention, the activity
of the parasympathetic nervous system and/or of the sympathetic
nervous system is determined dependent on time. Advantageously, the
feature of the condition is a series of heartbeats of the living
being, and the activity is determined by analyzing the time
intervals between the heartbeats. For this purpose, the heart rate
of the living being is preferably measured, and the heartbeat is
determined using first positive deflections of a ventricular
stimulus (R deflection). The invention further relates to a device
for carrying out the method.
Inventors: |
Wittling; Werner;
(Neunkirchen, DE) ; Wittling; Ralf Arne;
(Neunkirchen, DE) |
Family ID: |
44585471 |
Appl. No.: |
13/635248 |
Filed: |
March 18, 2011 |
PCT Filed: |
March 18, 2011 |
PCT NO: |
PCT/DE11/00291 |
371 Date: |
September 14, 2012 |
Current U.S.
Class: |
340/576 ;
600/509; 600/510; 600/521 |
Current CPC
Class: |
A61B 5/4035 20130101;
A61B 5/4836 20130101; A61B 5/0245 20130101; A61B 5/4884 20130101;
A61B 5/0456 20130101; A61B 5/04017 20130101 |
Class at
Publication: |
340/576 ;
600/509; 600/510; 600/521 |
International
Class: |
A61B 5/0456 20060101
A61B005/0456; G08B 23/00 20060101 G08B023/00; A61B 5/0402 20060101
A61B005/0402 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 19, 2010 |
DE |
10 2010 012 196.7 |
Aug 11, 2010 |
DE |
10 2010 034 055.3 |
Claims
1-15. (canceled)
16. A method for determining activity of the parasympathetic
nervous system and/or the sympathetic nervous system of the
autonomic nervous system of a living being, the method comprising
the steps of: determining a feature of the condition of the living
being is determined; and determining the activity from the feature
of the condition, wherein the activity of the parasympathetic
nervous system and/or the sympathetic nervous system is determined
as a function of time.
17. The method in accordance with claim 16, wherein the feature of
the condition of the living being is a series of heartbeats and
that the activity is determined by analyzing time intervals between
the heartbeats.
18. The method in accordance with claim 17, including making a
heart rate measurement, with the heartbeat being determined based
on first positive deflections of ventricular stimulation (R
deflection).
19. The method in accordance with claim 18, including making the
heart rate measurement by recording an electrocardiogram (EKG) of
the living being.
20. The method in accordance with claim 17, including analyzing
time intervals or time variations by a method of complex
demodulation method (CDM).
21. The method in accordance with claim 16, including determining
the activity of the parasympathetic nervous system based on
frequencies of 0.15 to 0.4 Hz and amplitudes associated with these
frequencies, and determining the activity of the sympathetic
nervous system based on frequencies of 0.04 to 0.15 Hz determined
by a method of complex demodulation and amplitudes associated with
these frequencies.
22. The method in accordance with claim 18, including determining
the activity in a period before, during and/or after stimulation of
the living being.
23. The method in accordance with claim 22, including determining
the activity after physical exercise, therapeutic, drug and/or
electrical stimulation, psychic stress and/or pain.
24. The method in accordance with claim 22, including carrying out
the stimulation as a function of the activity of the
parasympathetic nervous system and/or the sympathetic nervous
system.
25. The method in accordance with claim 22, including determining
the activity by analyzing the time intervals within a period of
time following a change in the stimulation.
26. The method in accordance with claim 25, wherein the period of
time is 40 seconds.
27. The method in accordance with claim 25, wherein the change in
the stimulation is termination or reduction of the stimulation.
28. The method in accordance with claim 16, wherein the living
being is a human being.
29. Equipment for determining activity of the parasympathetic
nervous system and/or the sympathetic nervous system of the
autonomic nervous system of a living being, comprising: a device
for determining a feature of the condition of the living being; and
a computer connected to the device for determining the activity
from the feature of the condition of the living being, wherein the
computer is operative to determine the activity of the
parasympathetic nervous system and/or the sympathetic nervous
system as a function of time.
30. The equipment in accordance with claim 29, wherein the device
is a device for measuring heartbeats of the living being.
31. The equipment in accordance with claim 29, wherein the computer
is operative to determine the activity by a method of complex
demodulation (CDM).
32. The equipment in accordance with claim 31, wherein the computer
is operative to determine the activity from valves of the intervals
between first positive deflections of a ventricle (R-R
interval).
33. The equipment in accordance with claim 31, wherein the computer
is operative to determine the activity by the method of complex
demodulation (CDM) based on certain frequencies of 0.15 to 0.4 Hz
and/or 0.04 to 0.15 Hz.
34. The equipment in accordance with claim 33, wherein the computer
is operative to determine the activity based on amplitudes
associated with the frequencies.
35. The equipment in accordance with claim 30, wherein the computer
is operative to determine the activity from a series of the
heartbeats within a period of time following a change in
stimulation.
36. The equipment in accordance with claim 35, wherein the period
of time is 40 seconds.
37. The equipment in accordance with claim 35, wherein the change
is stimulation is a termination or reduction of the
stimulation.
38. The method in accordance with claim 16, further including
determining an effect and/or influence on a physical condition of
an individual produced by administration of drugs or other
substances, determining an effect of a relaxation treatment or an
effect of stress factors, determining reactions to advertising
messages, or detecting an infection, hypertension, a change in
cholesterol, or an inflammatory process based on the determined
activity of the parasympathetic nervous system and/or the
sympathetic nervous system.
39. The method in accordance with claim 16, further including
continuously evaluating the ability of an individual to drive a
motor vehicle or operate machinery, controlling parameters of an
environment of the individual, or controlling interactive computer
games or television or video films based on the determined activity
of the parasympathetic nervous system and/or the sympathetic
nervous system.
40. The method in accordance with claim 39, wherein the
environmental parameters are selected from the group consisting of
lighting intensity, coloration or sounds in the environment.
Description
[0001] The invention concerns a method for determining the activity
of the parasympathetic nervous system and/or the sympathetic
nervous system of the autonomic nervous system of a living being,
especially a human being, in which a feature of the condition of
the living being is determined and recorded, and the activity is
determined from this feature of the condition.
[0002] The physical state of a living being, e.g., its health,
fitness or a stress state, is determined by, among other things,
its ability to adapt to stresses and to withstand them. This
adaptation occurs via the autonomic nervous system, which regulates
the heart rate, respiration, blood pressure, digestion and
metabolism as a function of the given stress. A division of the
autonomic nervous system whose activation promotes performance
readiness and responsiveness and the activation of energy reserves
is known as the sympathetic nervous system. The activation of
another division of the autonomic nervous system promotes rest and
recovery and energy storage. This division is known as the
parasympathetic nervous system, which acts as an antagonist to the
sympathetic nervous system. Numerous studies have shown that the
activity of the sympathetic nervous system and the parasympathetic
nervous system can be used to assess the functional capacity of
human beings. Since effects of activities of the sympathetic
nervous system or parasympathetic nervous system can be associated,
e.g., with variations of the time intervals between heartbeats,
their measurement can be used to determine the given activity.
[0003] In a method of the aforementioned type that is well known
through wide use, an electrocardiogram (EKG) of a person at rest is
recorded over a period of several minutes. The time intervals are
then analyzed by fast Fourier transform (FFT), and a frequency
spectrum is constructed. A low-frequency region of this frequency
spectrum, namely, 0.04 to 0.15 Hz, can be associated with the
activity of the sympathetic nervous system, since the influence of
the sympathetic nervous system on the heartbeat occurs in a
relatively slow rhythm. A region of higher frequency, namely 0.15
to 0.4 Hz, is associated with the activity of the parasympathetic
nervous system, which influences the heartbeat in a faster rhythm.
By analyzing the frequency spectrum, the activities of the
sympathetic nervous system and the parasympathetic nervous system
relative to each other can be determined, and conclusions can be
drawn about the physical and mental well-being of the
individual.
[0004] In another well-known method that is used to determine
fitness, a measurement is made of the amount of time needed for the
pulse rate of the individual to return to a previously determined
base rate after physical exercise (pulse recovery time). However,
this widely used method is inexact.
[0005] More exact but also very expensive methods are lactate
performance diagnosis and oxygen saturation analysis.
[0006] The objective of the invention is to develop a method with
which the physical state of the individual can be evaluated quickly
and simply.
[0007] In accordance with the invention, this objective is achieved
by determining the activity of the parasympathetic nervous system
and/or the sympathetic nervous system as a function of time.
[0008] The method of the invention makes it possible for changes in
the activity of the parasympathetic nervous system and/or the
sympathetic nervous system provoked by stimulation, for example,
physical exercise, therapeutic, drug and/or electrical stimulation,
psychic stress and/or pain, to be associated with specific points
in time.
[0009] From this it is possible to draw conclusions about physical
regeneration capacity and thus about the physical condition of the
individual, especially his health or physical functional
capacity.
[0010] It is advantageous to use a series of heartbeats of the
individual as the feature of his condition.
[0011] The activity of the parasympathetic nervous system and/or
the sympathetic nervous system can be determined by analyzing the
time intervals between the heartbeats.
[0012] It is advantageous to record an electrocardiogram and to
determine the heartbeat, preferably on the basis of the first
positive deflections of ventricular stimulation (R deflection).
Preferably, false signals of the measurement, caused, for example,
by patient movement, are corrected. Alternatively, the heartbeat
can be determined by picking up the pulse optically or
mechanically.
[0013] In a refinement of the method, the time intervals,
especially their variations, can be analyzed by the complex
demodulation method (CDM).
[0014] This is a nonlinear rime range method for a time series
analysis. While the aforementioned fast Fourier transform only
allows determination of superposed frequencies from measurement
over a prolonged period of time, with CDM it is also possible to
analyze unsteady and discontinuous signals. The amplitude and the
phase of a frequency component as a function of time are obtained
as the result.
[0015] A time series X(t) can be represented as follows:
X.sub.t=A.sub.t*cos[f.sub.0t+P.sub.t] (1) [0016] where
A.sub.t=slowly changing amplitude [0017] P.sub.t=slowly changing
phase
[0018] At a know frequency f.sub.0, (1) can be substituted with the
Euler equation:
X.sub.t=(1/2)A.sub.t
{exp[i(f.sub.0t+P.sub.t)]+exp[-i(f.sub.0t+P.sub.1)]}
If Y.sub.t=X.sub.t 2 exp(-if.sub.0t),
then Y.sub.t=A.sub.t[exp(iP.sub.t)+exp(-i{2f.sub.0t+P.sub.t})]
[0019] After a low-pass filtering of Y.sub.t, we obtain
y.sub.t=(1/2)A.sub.t exp(iP.sub.t) where A.sub.t=2|y.sub.t|
P.sub.t=tan.sup.-1[imag(h)/real(h)] where h=y.sub.t/|y.sub.t|
[0020] Viewed from the frequency range, the frequency band to be
analyzed is shifted to zero and then low-pass filtered. The
variation of the amplitude of the complex demodulation then
reproduces the intensity of the signal around the frequency
f.sub.0. The variation of the phase describes the relative
frequency deviation from the frequency f.sub.0.
[0021] While the determination of only the activity of the
parasympathetic nervous system, which is determined on the basis of
frequencies of 0.15 to 0.4 Hz determined by the method of complex
modulation and the amplitudes associated with these frequencies, is
adequate for obtaining a sufficiently valid result, alternatively
or additionally, the activity of the sympathetic nervous system can
be determined, preferably on the basis of the frequencies of 0.04
to 0.15 Hz and the amplitudes associated with these frequencies. A
reaction of the sympathetic nervous system to the stimulation can
be determined and related to the activity of the parasympathetic
nervous system.
[0022] The determination of activities at frequencies of 0.003 to
0.04 Hz is also conceivable. This allows even more exact
evaluation.
[0023] In addition to FFT and CDM, it is also conceivable for the
analysis to be carried out by means of the Hilbert transform,
in-phase and in-quadrature filtering (filtering with ideal band
pass and with the aid of quadrature modulation), phase-locked loop
demodulation (demodulation with the aid of a PLL circuit), or peak
amplitude and zero-crossing detection (determination of extreme
values and zero crossings).
[0024] The activity of the parasympathetic nervous system and/or
the sympathetic nervous system can be determined in a period of
time before, during and/or after stimulation of the individual.
However, in an especially preferred embodiment of the invention, it
is determined by analyzing the time intervals within a period of
time following a change in the stimulation, preferably a
termination or reduction of the stimulation. This period of time is
preferably at least 40 seconds. The reduction of the stimulation
can consist, for example, in the case of physical exercise, in a
period of relatively great output, for example, >300 W, being
followed by much lower output, for example, <70 W, or no output
at all.
[0025] It has been found that physical condition can be assessed on
the basis of the change in activity of the parasympathetic nervous
system that follows the change in stimulation. In addition, by
repeating the method of the invention at greater intervals of time,
e.g., regularly after several days, it is possible to assess the
development of physical condition, for example, after taking drugs
or other substances, or fitness, for example, after training with a
certain training method. Results of the determination of the
activity of the parasympathetic nervous system and/or the
sympathetic nervous system are advantageously evaluated with
consideration of the age of the individual and/or they can be
evaluated with reference to normal values.
[0026] In an especially preferred embodiment of the invention, the
stimulation is carried out as a function of the activity of the
parasympathetic nervous system and/or the sympathetic nervous
system. In this way, the duration and/or intensity of the
stimulation can be adapted to the response of the individual to the
stimulation. The interaction between the stimulation and the
activity of the parasympathetic nervous system and/or the
sympathetic nervous system can be used in making the
evaluation.
[0027] It is advantageous to end the stimulation when the
parasympathetic nervous system and/or the sympathetic nervous
system shows a certain activity. It is conceivable that the
stimulation can be ended when the given activity during a certain
period of time, preferably during a period of 10 seconds, has a
certain value. Preferably, the stimulation is ended when the
parasympathetic nervous system is not active during this period of
time.
[0028] Alternatively, the stimulation can be carried out upon
expiration of a predetermined period of time, with the individual
preferably being stressed by physical exercise on an ergometer. In
this connection, the work output to be produced is preferably
increased incrementally, in a way that is well known from exercise
electrocardiography, until a certain maximum work load has been
reached.
[0029] The invention also concerns equipment for determining the
activity of the parasympathetic nervous system and/or the
sympathetic nervous system of the autonomic nervous system of a
living being, especially a human being, which includes a device for
determining and/or recording a feature of the condition of the
living being and a computer connected to this device for
determining the activity from the feature of the condition of the
living being.
[0030] In equipment of this type, which is already widely used, the
measurements recorded by the EKG machine are transmitted to the
computer, and after the measurement, software is used to analyze
the measurement results by means of the fast Fourier transform,
and, as described at the beginning, the frequency spectrum is
associated with the activity of the sympathetic nervous system or
the parasympathetic nervous system.
[0031] In accordance with the invention, the computer is provided
for carrying out a time-dependent determination of the activity of
the parasympathetic nervous system and/or the sympathetic nervous
system, preferably by means of a suitable program.
[0032] The equipment is suitable for evaluating the physical
condition of the individual, e.g., his health, his fitness, or a
state of stress.
[0033] Advantageously, the means for determining the feature of the
condition of the individual is a device for measuring his
heartbeats, preferably a heart rate monitor or an EKG machine.
[0034] In one modification of the invention, the computer is
designed to determine the activity from the time intervals between
the heartbeats, preferably from information acquired from the EKG
machine.
[0035] In one modification of the invention, the computer is
designed to determine the activity by the method of complex
demodulation (CDM), preferably on the basis of frequencies of 0.15
to 0.4 Hz and/or 0.04 to 0.15 Hz and of amplitudes associated with
these frequencies.
[0036] In addition, the computer can be designed to determine
activities at frequencies of 0.003 to 0.04 Hz.
[0037] It is advantageous for the equipment to include a device for
stimulation of the individual, preferably an ergometer, which is
preferably connected to the computer. The physical work performed
by the individual can be determined with the ergometer and/or an
amount of physical work to be performed can be preassigned to the
individual. The data measured with the ergometer can be transmitted
to the computer, and the computer is possibly set up to control the
ergometer and especially to adjust the amount of physical work to
be performed.
[0038] In a preferred embodiment, the device for providing
stimulation and especially the intensity of the stimulation can be
controlled as a function of the activity of the parasympathetic
nervous system and/or the sympathetic nervous system. In
particular, it is possible to adapt the physical work to be
performed to the activity of the parasympathetic nervous
system.
[0039] In one modification of the invention, the computer is
designed to determine the activity of the parasympathetic nervous
system and/or the sympathetic nervous system from the measurement
of the feature of the condition of the individual during a period
of time following termination of the stimulation of the individual.
This period of time preferably lasts at least 40 seconds.
[0040] The computer can advantageously be a mobile device, e.g., a
laptop or a device that can be worn on the body, such as a smart
phone, or it can be of a sufficiently small size that it can be
attached to the body, e.g., like a wrist watch. The heartbeats can
be determined in an already well-known way with a chest strap that
determines the heartbeats by means of two integrated skin
electrodes. It is advantageous to connect the chest strap to the
computer in such a way that information determined by means of the
chest strap can be transmitted to the computer, e.g., by radio.
[0041] In a modification of the invention, the method and equipment
described above are used to carry out a biofeedback process, in
which the activity of the parasympathetic nervous system and/or the
sympathetic nervous system of the individual is measured, and the
measurement results are continuously displayed, e.g., on a display
screen, so that the individual can watch them. The advantage of
this method is that allows the individual to learn to control the
activity of the parasympathetic nervous system and/or the
sympathetic nervous system, e.g., by breathing technique, autogenic
training or the like.
[0042] Furthermore, the method and equipment can be used to
determine an effect and/or influence on the physical condition of
the individual produced by the administration of drugs or other
substances, e.g., caffeine, alcohol or nicotine, or to determine an
effect of relaxation techniques, e.g., breathing therapy,
acupuncture, yoga or progressive muscle relaxation, effects of
stress factors, or reactions to advertising messages, especially
for marketing research purposes.
[0043] In addition, the method and equipment can be used to detect
and possibly determine an infection, hypertension, a change in
cholesterol, or an inflammatory process.
[0044] Another possible application is continuous evaluation of the
ability of an individual to drive a motor vehicle or operate
machinery.
[0045] The method or the equipment can also be used to control
parameters of an environment of an individual, e.g., lighting
intensity, coloration or sounds, according to the physical state of
the individual. For this purpose, the equipment is advantageously
connected with a control device by which the parameters can be
adjusted.
[0046] Finally, the equipment or the method can be used for
controlling interactive computer games or television or video
films.
[0047] The invention will now be explained in greater detail with
reference to specific embodiments and to the accompanying drawings
related to these specific embodiments.
[0048] FIG. 1 is a schematic representation of the equipment of the
invention.
[0049] FIG. 2 is a graph that shows the results of measurements by
the method of the invention.
[0050] FIGS. 3 to 5 are graphs of results of a study in which the
method of the invention was used.
[0051] FIG. 1 shows equipment of the invention, which comprises a
bicycle ergometer 1, an EKG machine 2, and a computer 3 with a
monitor 4. A person 5 is shown sitting on the bicycle ergometer for
the purpose of illustration.
[0052] The computer 3 is connected with the bicycle ergometer 1 in
such a way that the physical work performed by the person 5 is
displayed on the monitor 4 and can be stored as a function of time.
In addition, the computer 3 can be used to preassign an amount of
work to be performed by the person 5. For this purpose, the
computer 3 can also adjust the work to be performed on the bicycle
ergometer 1, for example, by increasing the resistance of the
pedals of the bicycle ergometer 1.
[0053] Other types of ergometers can be used as alternatives to the
bicycle ergometer, for example, cross trainer machines, rowing
ergometers, treadmills and home exercise equipment.
[0054] The EKG machine 2 includes electrodes arranged on the body
surface of the person 5 and is likewise connected to the computer
3. An electrocardiogram recorded with the EKG machine 2 is
transmitted to the computer 3 and stored there.
[0055] Alternatively, the equipment of the invention can include a
device for monitoring the heart rate optically and/or mechanically.
Devices of this type include especially such well-known devices as
a chest strap or sensors mounted in the hand grips of the bicycle
ergometer.
[0056] It is possible for the EKG machine 2 or the aforementioned
devices for monitoring the heart rate and the computer 3 and
monitor 4 to be integrated in the bicycle ergometer or other
specified types of ergometers.
[0057] When the method of the invention is carried out, the
computer runs a program that is designed to store and evaluate
measurement results and to display the measurement results and
evaluations. In addition, it guides the person 5 through the
method.
[0058] First, as in the case of an exercise EKG, the person 5
produces an incrementally increasing work output by pedaling the
bicycle ergometer 1. Within the first minute, 30 W are generated,
and then the work output is increased minute by minute to 150 W, so
that an output of 150 W is being produced within five minutes. At
the end of the fifth minute, the person 5 stops pedaling and
remains at rest while his heartbeat is recorded. Alternatively, the
person 5 can continue to pedal at a much lower work output of
<70 W and preferably <50 W.
[0059] Alternatively, the work load can also be increased
continuously.
[0060] In addition, the duration of the exercise can be varied,
e.g., on the basis of an estimate of the physical functional
capacity of the person 5.
[0061] To obtain a valid result, at least 40 seconds must be
recorded. However, valuable information can be obtained especially
from measurements of the first 300 seconds.
[0062] By means of the aforesaid program, the measurement results
are stored, the measurement result is tested for measurement errors
that may have occurred, and these errors are corrected. An analysis
is then undertaken by the method of complex demodulation (CDM).
Frequencies superposed in the rhythm of the heartbeats and
amplitudes associated with these frequencies are determined and
assigned to an activity of the parasympathetic nervous system that
lies in the frequency range of 0.15 to 0.4 Hz and possibly to an
activity of the sympathetic nervous system that lies in a frequency
range of 0.04 to 0.15 Hz. The behavior of the given activity as a
function of time can be graphically represented on the monitor 4,
as shown, for example, in the graph in FIG. 2. Besides the results
of the analysis, the software can indicate normal values for the
physical characteristics of the person 5, in relation to which the
person's fitness can be assessed.
[0063] In the graph according to FIG. 2, the activity of the
parasympathetic nervous system, as determined by the method
described here, is graphed for varyingly well-trained persons A, B,
C, D and E as a function of time after termination of the physical
exercise described above. Person A participates in sports activity
for more than 9 hours per week, person B for 5-9 hours, person C
for 2-5 hours, person D for 0.5-2 hours, and person E for less than
0.5 hours. As the graph shows, there are clear differences between
the differently well-trained persons with respect to the activity
of the parasympathetic nervous system as a function of time. Thus,
the highly physically trained person A shows a greater rate of rise
and a greater maximum amplitude than the other test subjects. The
graph shows that the less well trained the persons are, the slower
the rate of rise, the lower the maximum amplitude, and the longer
the period of time during which the amplitude rises.
[0064] In a study with 37 test subjects with an average age of
26.22 years, of whom 19 where female and 18 were male, it was found
that the method of the invention was able to determine significant
differences between the test subjects as a function of their weekly
physical activity. The test subjects were divided into three
groups. The first group participated in sports activity for 0-2.5
hours per week, the second for 3-4 hours per week, and the third
for 4.5-7.5 hours per week.
[0065] As FIG. 3 shows, the rate of rise described above is
significantly lower in the test subjects who participated in sports
activities for only 0-2.5 hours per week than that of the other
test subjects. Moreover, the rate of rise for the test subjects
that had 4.5-7.5 hours of sports activity per week is higher than
that of the test subjects that had 3-4 hours of sports activity per
week.
[0066] Similar differences are found for the maximum amplitude
level of the parasympathetic activity, which is shown in FIG.
4.
[0067] The graph in FIG. 5 shows that the period of time during
which the amplitude rises is significantly higher for persons with
the least amount of sports activity than for the persons with
greater training.
[0068] The method of the invention is suitable not only for a
one-time evaluation of the physical condition of a person but also
and especially for monitoring a person's condition over an extended
period of time, in which case the method would be carried out at
regular intervals and the results compared with previous results.
Insufficient activation of the parasympathetic nervous system could
thus give an early indication of the onset of cardiovascular
diseases.
[0069] The method also offers the advantageous possibility, for
example, of evaluating the effect of drugs or therapies or the
effectiveness of a certain training method.
[0070] It is also conceivable that the method could be used for
evaluating the health of animals. This method could be of interest
especially for testing the fitness of competitive animals, such as
horses, dogs, or camels. The equipment of the invention can be
adapted to the individual animal species.
[0071] In another embodiment of the invention, the activity of the
parasympathetic nervous system and possibly the sympathetic nervous
system of the person 5 is already determined during and possibly
even before the person first starts exercising on the bicycle
ergometer 1. The activity of the parasympathetic nervous system
before or at the beginning of exercise and its response to the
physical load, especially its change and/or the time until a
certain activity is reached, especially as a function of the work
output produced or to be produced, is a measure of the physical
fitness of the person 5. One measure, for example, is the rate of
decline of the parasympathetic nervous system activity, measured as
the quotient of the activity before or at the beginning of exercise
and the length of time until inactivity of the parasympathetic
nervous system is reached.
[0072] Furthermore, information obtained in this way for the
activity of the parasympathetic nervous system during the initial
exercise can be used to control the level of work to be performed
by the person 5.
[0073] For example, the incrementally increasing work to be
performed on the bicycle ergometer 1 can be ended exactly when the
parasympathetic nervous system has a certain activity over a period
of e.g., 10 seconds, or is no longer active. The exercise of a less
well trained person is then ended earlier than that of a person in
better training.
[0074] Alternatively, it is possible for the work to be performed
on the bicycle ergometer 1 to be controlled as a function of the
activity of the parasympathetic nervous system measuring during
exercise. This makes it possible to ensure that for the individual
being tested, the parasympathetic nervous system has a certain
activity as a function of time during the exercise phase. The work
to be performed by a well-trained person is then increased more
rapidly than the work to be performed by a less fit person.
[0075] The initial exercise can be followed by measurement at rest
or at a low work load as described above.
[0076] When the exercise is controlled as a function of the
activity of the parasympathetic nervous system, it becomes possible
to adjust the exercise phase to the individual person who is being
tested and to create comparable conditions for the measurement at
rest or at a lower work load.
[0077] To make it possible to control the amount of work to be
performed as a function of the activity of the parasympathetic
nervous system, the computer 3 is designed in such a way that the
work to be performed can be directly controlled on the basis of the
evaluations of the measurement results, i.e., on the basis of the
activity of the parasympathetic nervous system determined from the
measurement results. The computer 3 determines the activity of the
parasympathetic nervous system and controls the bicycle ergometer 1
as a function of the measurement, i.e., during the time of the work
load on the person 5 on the bicycle ergometer 1.
* * * * *